Site Records

Corsham, Wiltshire

By Les Hayward

This part of Wiltshire is well known as a source of fine Bath stone, which has
been quarried for many centuries. The stone was mainly mined underground.
Due to its consistency, the ceilings of the old workings have a
considerable span, leaving large galleries and tunnels where the stone
has been removed.

In both the first and second World Wars, thoughts turned to the problem of
storing a vast amount of ammunition safe from bombing.
Underground storage seemed to be the logical method, so existing
mines and quarries throughout the country were investigated.

The quarries of Wiltshire were selected amongst others in the country.
Storage of ammunition, however, is a complex business. The access to the underground
areas needed improvement and waste stone had to be cleared. Irregular
workings needed to be engineered into straight roads, and
roofs required considerable strengthening.

A further and little considered problem was that of the storage environment.
The mines have a fairly constant temperature of 50 °F (10 °C), but the
main problem for storage is the very high humidity. This precludes all but
very short-term storage of most materials. Some quarries, where conditions
were not too bad, had no air conditioning. Ridge Quarry was used both in the
first and second world wars with little more than rudimentary engineering
to produce the storage bays.

The greatest undertaking was to be the Central Ammunition Depot at Corsham.
The name belies the fact that it was anything but central, since mines
at Monkton Farleigh and Eastlays were employed, as well as the mighty Tunnel
Quarry at Corsham.

Tunnel Quarry was a vast stone mine adjacent to the famous Box railway tunnel.
At the time of adoption it already had the advantage of a railway junction leading
underground from a junction alongside the Box tunnel entrance. The mine at
Monkton Farleigh was a very different matter, being on the top of a hill just
behind Brown's Folly and with poor road access. Monkton was initially served
by an aerial ropeway leading down the hill some two miles to Farleigh Down
sidings. Later, a tunnel was constructed to the sidings - a most remarkable
engineering work, and materials were loaded from train to the depot by
conveyor belts. These belts were then used throughout the depots for internal
distribution.

Unlike Ridge, the quarries at Tunnel, Monkton and Eastlays were engineered to
a very high standard. The roads were laid in straight lines and were covered
with rolled asphalt. Some bays (District 14) were constructed as regularly
shaped rooms by a massive underpinning operation. Elsewhere pillars were shaped
as regularly as possible and the whole wall and ceiling surface was sprayed
with a light coloured paint. Air conditioning of various types was tried and
expanded through the life of the establishments and the complexes were well
provided with electric lighting and sewerage systems. Each establishment
had a large standby diesel generating station.

After de-commissioning in the 1960s, and after a few abortive developments,
Eastlays was used as a bonded warehouse and remains thus, largely intact.
Monkton was a different matter and had a very complex series of attempted
developments. For a few years there was a very good museum. Sadly, as a
result of very strange actions by the subsequent owners, the museum was
terminated and a period of comprehensive vandalism reduced a fine establishment
to a mess. Currently, several districts at Monkton Farleigh have been leased
by Wansdyke Security and have thus been rescued from further destruction, but
districts 19 and 20 remain derelict.

Tunnel Quarry has remained in MoD hands. Part is known as the Corsham
Computer Centre and part is used by RAF Rudloe Manor. Adjacent to this and
linked underground are Browns Quarry, former RAF Sector Command (Now CDCN)
and Spring Quarry. Spring Quarry was a Ministry of Aircraft Production factory and in
later years a store for the Royal Navy. Part of Spring Quarry was developed
as one of the Hawthorn Central Government (War) Headquarters (CGHQ) sites and this
still exists and is maintained on a care & maintenance basis. The rail link
into Tunnel was closed when the site ceased to be used for ammunition storage.

For a definitive illustrated history of these sites, see
The Secret Underground City by
N J McCamley.